Systems and Methods for Coupling an Ultrasound Source to Tissue

ABSTRACT

This disclosure provides systems and methods for sensing coupling of an ultrasound source to a target and for providing a constant average output of power from an ultrasound source. The systems and methods can include a frequency sweep function. The systems and methods can also include receiving reflected energy from an acoustic window and determining a feedback using the reflected energy. The systems and methods can also include comparing the feedback with a threshold level and using the comparison to determine if the ultrasound source is coupled with a target.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation to U.S. patent application Ser. No.15/293,361, filed Oct. 14, 2016, which is a divisional of U.S. patentapplication Ser. No. 13/547,023, filed Jul. 11, 2012, issued as U.S.Pat. No. 9,504,446, which claims priority to and the benefit of U.S.Provisional Patent Application Ser. No. 61/506,609, entitled “Systemsand Methods for Monitoring Ultrasound Power Efficiency,” filed Jul. 11,2011; and U.S. Provisional Patent Application Ser. No. 61/506,610,entitled “Methods and Systems for Controlling Acoustic Energy Depositioninto a Medium,” filed Jul. 11, 2011; all of which are incorporated byreference herein in their entireties.

U.S. patent application Ser. No. 13/547,023 is also a continuation inpart of and claims priority to and the benefit of U.S. patentapplication Ser. No. 13/136,544, entitled “Systems and Methods forUltrasound Treatment,” filed Aug. 2, 2011, issued as U.S. Pat. No.9,149,658, which claims priority to and the benefit of U.S. ProvisionalPatent Application Ser. No. 61/369,782, entitled “Systems and Methodsfor Ultrasound Treatment”, filed Aug. 2, 2010; U.S. Provisional PatentApplication Ser. No. 61/369,793, entitled “System and Method forTreating Sports Related Injuries”, filed Aug. 2, 2010; U.S. ProvisionalPatent Application Ser. No. 61/369,806, entitled “System and Method forTreating Sports Related Injuries”, filed Aug. 2, 2010; U.S. ProvisionalPatent Application Ser. No. 61/370,095, entitled “System and Method forTreating Cartilage”, filed Aug. 2, 2010; all of which are incorporatedby reference herein.

BACKGROUND

Coupling of a treatment system to tissue is important for clinicalefficiency of the desired treatment. In addition, using a treatmentsystem that is not coupled to tissue may cause safety concerns. Further,if a treatment system is not properly coupled to the tissue may causestability and performance issues. Various contact sensors have been usedto determine if a treatment system is coupled to targeted tissue.However, these contact sensors typically use mechanical methods todetermine if a treatment system is coupled to the tissue. Accordingly,new approaches for determining whether a treatment system is coupled totargeted tissue are needed.

SUMMARY

Various embodiments described herein provide methods and systems formonitoring ultrasound energy. Various embodiments provide a method ofsensing coupling of an ultrasound source to a target. In someembodiments, the method comprises providing an ultrasound sound sourcecomprising a transducer, an acoustically transparent standoff, anacoustic window at a bottom surface of the standoff, and a frequencysweep function coupled to the transducer. In some embodiments, themethod can comprise emitting ultrasound energy from the transducer;receiving reflected energy; frequency sweeping the transducer;determining the feedback from the frequency sweep is above a thresholdlevel; and determining of the source is coupled to the target.

In some embodiments, if the feedback from the frequency is above thethreshold level, then the source is not coupled to the target. In someembodiments, if the feedback from the frequency is below the thresholdlevel, then the source is coupled to the target.

Various embodiments provide a system for determining whether anultrasound source is coupled to a target. In some embodiments, thesystem comprises an ultrasound source comprising a transducer; anacoustically transparent standoff coupled to the transducer; a halfwavelength acoustic window at a bottom surface of the standoff, and afrequency sweep function coupled to the transducer.

Various embodiments provide a system for providing a constant averageoutput of power from an ultrasound source. In some embodiments, thesystem comprises an ultrasound transducer coupled to a power supply; acontroller in communication with the power supply; a chirp function incommunication with and operable to monitor the ultrasound transducer; afeedback loop from the chirp function to the controller. In someembodiments, the controller is operable to change a parameter on thetransducer based on the feedback to provide a constant average output ofpower from the ultrasound transducer.

DRAWINGS

The present disclosure will become more fully understood from thedescription and the accompanying drawings, wherein:

FIG. 1 is a cross sectional view illustrating tissue layers andultrasound energy directed to a portion of the tissue layers, inaccordance with various non-limiting embodiments;

FIG. 2 is a graph illustrating ultrasound efficiency at a frequency, inaccordance with various non-limiting embodiments;

FIG. 3 is a graph illustrating ultrasound efficiency a frequency, inaccordance with various non-limiting embodiments;

FIG. 4 is a block diagram illustrating a system in accordance withvarious non-limiting embodiments;

FIG. 5 is a block diagram illustrating a system in accordance withvarious non-limiting embodiments;

FIG. 6 is a block diagram illustrating a system in accordance withvarious non-limiting embodiments.

FIG. 7 is a block diagram illustrating a system in accordance withvarious non-limiting embodiments;

FIG. 8 is a block diagram illustrating a system in accordance withvarious non-limiting embodiments;

FIG. 9 is a diagram illustrating a transducer system coupled to tissuein accordance to various non-limiting examples;

FIG. 10 is a diagram illustrating a transducer system not coupled totissue in accordance to various non-limiting examples;

FIG. 11 is a graph illustrating resistance over time for a transducersystem coupled to tissue in accordance with various non-limitingembodiments; and

FIG. 12 is a graph illustrating resistance over time for a transducersystem not coupled to tissue in accordance with various non-limitingembodiments.

DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the various embodiments, their application, or uses.As used herein, the phrase “at least one of A, B, and C” should beconstrued to mean a logical (A or B or C), using a non-exclusive logical“or.” As used herein, the phrase “A, B and/or C” should be construed tomean (A, B, and C) or alternatively (A or B or C), using a non-exclusivelogical “or.” It should be understood that steps within a method may beexecuted in different order without altering the principles of thepresent disclosure.

The drawings described herein are for illustrative purposes only ofselected non-limiting embodiments and not all possible implementations,and are not intended to limit the scope of any of the variousembodiments disclosed herein or any equivalents thereof. It isunderstood that the drawings are not drawn to scale. For purposes ofclarity, the same reference numbers will be used in the drawings toidentify similar elements.

The various embodiments may be described herein in terms of variousfunctional components and processing steps. It should be appreciatedthat such components and steps may be realized by any number of hardwarecomponents configured to perform the specified functions. For example,various embodiments may employ various medical treatment devices, visualimaging and display devices, input terminals and the like, which maycarry out a variety of functions under the control of one or morecontrol systems or other control devices. In addition, the embodimentsmay be practiced in any number of medical contexts and that the variousembodiments relating to a method and system for acoustic energydeposition in tissue, as described herein, are merely indicative of oneof the many applications for the invention. For example, the principles,features and methods discussed may be applied to any medicalapplication. Further, various aspects of the various embodiments may besuitably applied to cosmetic applications. Moreover, some of theembodiments may be applied to cosmetic enhancement of skin and/orvarious soft tissue layers.

Various embodiments provide methods and systems to adjust a temperatureof a transducer, in order to maintain maximum efficiency of powerapplied by the transducer. Some embodiments provide methods and systemsto minimize or eliminate temperature saturation of a transducer duringthe delivery of power to the transducer. In some embodiments, methodsand systems can control a temperature of a transducer to maintain adesired frequency of energy transmission at a maximum power.

Various embodiments provide methods and systems to adjust a temperatureof a transducer, in order to maintain maximum efficiency of powerapplied by the transducer. Some embodiments provide methods and systemsto minimize or eliminate temperature saturation of a transducer duringthe delivery of power to the transducer. In some embodiments, methodsand systems can control a temperature of a transducer to maintain adesired frequency of energy transmission at a maximum power.

Some embodiments provide a method of providing ultrasound energy havinga stable power output. The method can comprise providing ultrasoundenergy from a ultrasound transducer; determining a power level thresholdof the ultrasound energy; monitoring a power level of the ultrasoundenergy over time of the ultrasound energy; communicating a power levelto a controller; adjusting the frequency of the ultrasound energy upon achange in the power level; and maintaining the power level threshold ofthe ultrasound energy.

In some embodiments, the method can further comprise emitting theultrasound energy at a specific frequency and correcting the frequencyto the specific frequency upon a change in the power level. In someembodiments, the method can comprise changing power provided to atransducer providing the ultrasound energy based on the adjusting thefrequency of the ultrasound energy. In some embodiments, the method cancomprise terminating the providing the ultrasound energy upon a changeof the power level above the power level threshold.

Some embodiments provide a method of providing ultrasound energy havinga stable power output. The method can comprise providing ultrasoundenergy from an ultrasound transducer; determining a power levelthreshold of the ultrasound energy; monitoring a temperature of theultrasound transducer over time; communicating the temperature to acontroller; adjusting the frequency of the ultrasound energy upon achange in the temperature; and maintaining the power level threshold ofthe ultrasound energy.

In some embodiments, the method can further comprise determining atemperature threshold of the ultrasound transducer and terminating theproviding ultrasound energy when the temperature is above thetemperature threshold.

In some embodiments, the method can further comprise emitting theultrasound energy at a specific frequency and correcting the frequencyto the specific frequency upon the change of temperature. In someembodiments, the method can comprise terminating the providing theultrasound energy upon a change of the power level above the power levelthreshold. In some embodiments, the method can further comprisedetermining a temperature threshold of the ultrasound transducer andterminating the providing ultrasound energy when a temperature of theultrasound transducer is above the temperature threshold.

Some embodiments provide a method of providing ultrasound energy havinga stable power output. The method can comprise providing ultrasoundenergy from an ultrasound transducer; determining a voltage threshold ofthe ultrasound energy; monitoring a voltage of the ultrasound transducerover time; communicating the voltage to a controller; adjusting thefrequency of the ultrasound energy upon a change in the voltage; andmaintaining the power level threshold of the ultrasound energy.

In some embodiments, the method can further comprise determining atemperature threshold of the ultrasound transducer and terminating theproviding ultrasound energy when the temperature of the ultrasoundtransducer is above the temperature threshold.

In some embodiments, the method can further comprise emitting theultrasound energy at a specific frequency and correcting the frequencyto the specific frequency upon the change of voltage. In someembodiments, the method can comprise terminating the providing theultrasound energy upon a change of the power level above the power levelthreshold.

Some embodiments provide a method of providing ultrasound energy havinga stable power output. The method can comprise providing ultrasoundenergy from a ultrasound transducer; determining a voltage threshold ofthe ultrasound energy; monitoring a voltage of the ultrasound transducerover time; communicating the voltage to a controller; adjusting thefrequency of the ultrasound energy upon an change in the voltage;monitoring a power level of the ultrasound energy over time of theultrasound energy; communicating a power level to a controller;adjusting the frequency of the ultrasound energy upon a change in thepower level; and maintaining the power level threshold of the ultrasoundenergy.

In some embodiments, the method can further comprise determining atemperature threshold of the ultrasound transducer and terminating theproviding ultrasound energy when the temperature of the ultrasoundtransducer is above the temperature threshold.

In some embodiments, the method can further comprise emitting theultrasound energy at a specific frequency and correcting the frequencyto the specific frequency upon the change of voltage. In someembodiments, the method can comprise terminating the providing theultrasound energy upon a change of the power level above the power levelthreshold.

Some embodiments provide a method of providing ultrasound energy havinga stable power output. The method can comprise providing ultrasoundenergy from a ultrasound transducer; monitoring a power level of theultrasound energy over time of the ultrasound energy; communicating apower level to a controller; adjusting the frequency of the ultrasoundenergy upon a change in the power level; monitoring a temperature of theultrasound transducer over time; communicating the temperature to acontroller; adjusting the frequency of the ultrasound energy upon anchange in the temperature; and maintaining the power level threshold ofthe ultrasound energy.

In some embodiments, the method can further comprise determining atemperature threshold of the ultrasound transducer and terminating theproviding ultrasound energy when the temperature of the ultrasoundtransducer is above the temperature threshold.

In some embodiments, the method can further comprise emitting theultrasound energy at a specific frequency and correcting the frequencyto the specific frequency upon the change of voltage. In someembodiments, the method can comprise terminating the providing theultrasound energy upon a change of the power level above the power levelthreshold.

Some embodiments provide a method of providing ultrasound energy havinga stable power output. The method can comprise providing ultrasoundenergy from a ultrasound transducer; determining a voltage threshold ofthe ultrasound energy; monitoring a voltage of the ultrasound transducerover time; communicating the voltage to a controller; adjusting thefrequency of the ultrasound energy upon an change in the voltage;monitoring a power level of the ultrasound energy over time of theultrasound energy; communicating a power level to a controller;adjusting the frequency of the ultrasound energy upon a change in thepower level; monitoring a temperature of the ultrasound transducer overtime; communicating the temperature to a controller; adjusting thefrequency of the ultrasound energy upon an change in the temperature;and maintaining the power level threshold of the ultrasound energy.

In some embodiments, the method can further comprise determining atemperature threshold of the ultrasound transducer and terminating theproviding ultrasound energy when the temperature of the ultrasoundtransducer is above the temperature threshold.

In some embodiments, the method can further comprise emitting theultrasound energy at a specific frequency and correcting the frequencyto the specific frequency upon the change of voltage. In someembodiments, the method can comprise terminating the providing theultrasound energy upon a change of the power level above the power levelthreshold.

In some embodiments, temperature can be monitored by monitoring changesin time of flight of the ultrasound energy from the transducer. In someembodiments, temperature can be monitored by a piezoelectric sensor thatmay be a portion of transducer, as described herein. In variousembodiments, a controller may use a look up table to change a parameter.In some embodiments, controller can employ hardware, software, or acombination of both to change a parameter such as power, voltage orcurrent.

With reference to FIG. 1, a cross sectional view of tissue layers andultrasound energy directed to at least one of the tissue layers,according to various embodiments of the present invention, isillustrated. The tissue layers illustrated are skin surface 204,epidermal layer 202, dermis layer 206, fat layer 208, SMAS layer 210,and muscle and connective tissue layer 212. Ultrasound probe 205transmits ultrasound energy 220 transmitting in ROI 215. In variousembodiments, ultrasound probe 205 is capable of transmitting ultrasoundenergy 220 transmitting at variable depths in ROI 215, such as, forexample, the depths described herein. Ultrasound probe 205 is capable oftransmitting therapeutic ultrasound energy as a single frequency,variable frequencies, or a plurality of frequencies, such as, forexample, within the frequency ranges described herein. Ultrasound probe205 is capable of transmitting ultrasound energy 220 transmitting forvariable time periods or to pulse the transmission over time, such as,for example, those time intervals described herein. Ultrasound probe 205is capable of providing various energy levels of therapeutic ultrasoundenergy, such as, for example, the energy levels described herein.

Ultrasound probe 205 may be individual hand-held device, or may be partof a treatment system or part of cosmetic enhancement system. Theultrasound probe 205 can provide both therapeutic ultrasound energy andimaging ultrasound energy. However, ultrasound probe 205 may provideonly therapeutic ultrasound energy. Ultrasound probe 205 may comprise atherapeutic transducer and a separate imaging transducer. Ultrasoundprobe 205 may comprise a transducer or a transducer array capable ofboth therapeutic and imaging applications. According an alternativeembodiment, ultrasound probe 205 is coupled directly to one of thetissue layers, as opposed to skin surface 204 to treat the tissue layer.For example, ultrasound probe 205 can be integrated to or attached to atool, such as, for example, an arthroscopic tool, laparoscopic tool, oran endoscopic tool that may be inserted into a patient's body withminimal invasiveness.

In various embodiments, the ultrasound energy level is in a range ofabout 0.1 joules to about 500 joules in order to create an ablativelesion. However, the ultrasound energy 108 level can be in a range offrom about 0.1 joules to about 100 joules, or from about 1 joules toabout 50 joules, or from about 0.1 joules to about 10 joules, or fromabout 50 joules to about 100 joules, or from about 100 joules to about500 joules, or from about 50 joules to about 250 joules.

Further, the amount of time ultrasound energy is applied at these levelsvaries in the range from approximately 1 millisecond to several minutes.However, a range can be from about 1 millisecond to about 5 minutes, orfrom about 1 millisecond to about 1 minute, or from about 1 millisecondto about 30 seconds, or from about 1 millisecond to about 10 seconds, orfrom about 1 millisecond to about 1 second, or from about 1 millisecondto about 0.1 seconds, or about 0.1 seconds to about 10 seconds, or about0.1 seconds to about 1 second, or from about 1 millisecond to about 200milliseconds, or from about 1 millisecond to about 0.5 seconds.

The frequency of the ultrasound energy can be in a range from about 0.1MHz to about 100 MHz, or from about 0.1 MHz to about 50 MHz, or fromabout 1 MHz to about 50 MHz or about 0.1 MHz to about 30 MHz, or fromabout 10 MHz to about 30 MHz, or from about 0.1 MHz to about 20 MHz, orfrom about 1 MHz to about 20 MHz, or from about 20 MHz to about 30 MHz.

The frequency of the ultrasound energy can be in a range from about 1MHz to about 12 MHz, or from about 5 MHz to about 15 MHz, or from about2 MHz to about 12 MHz or from about 3 MHz to about 7 MHz.

In some embodiments, the ultrasound energy can be transmitted to depthsat or below a skin surface in a range from about 0 mm to about 150 mm,or from about 0 mm to about 100 mm, or from about 0 mm to about 50 mm,or from about 0 mm to about 30 mm, or from about 0 mm to about 20 mm, orfrom about 0 mm to about 10 mm, or from about 0 mm to about 5 mm. Insome embodiments, the ultrasound energy can be transmitted to depthsbelow a skin surface in a range from about 5 mm to about 150 mm, or fromabout 5 mm to about 100 mm, or from about 5 mm to about 50 mm, or fromabout 5 mm to about 30 mm, or from about 5 mm to about 20 mm, or fromabout 5 mm to about 10 mm. In some embodiments, the ultrasound energycan be transmitted to depths below a skin surface in a range from about10 mm to about 150 mm, or from about 10 mm to about 100 mm, or fromabout 10 mm to about 50 mm, or from about 10 mm to about 30 mm, or fromabout 10 mm to about 20 mm, or from about 0 mm to about 10 mm.

In some embodiments, the ultrasound energy can be transmitted to depthsat or below a skin surface in the range from about 20 mm to about 150mm, or from about 20 mm to about 100 mm, or from about 20 mm to about 50mm, or from about 20 mm to about 30 mm. In some embodiments, theultrasound energy can be transmitted to depths at or below a skinsurface in a range from about 30 mm to about 150 mm, or from about 30 mmto about 100 mm, or from about 30 mm to about 50 mm. In someembodiments, the ultrasound energy can be transmitted to depths at orbelow a skin surface in a range from about 50 mm to about 150 mm, orfrom about 50 mm to about 100 mm. In some embodiments, the ultrasoundenergy can be transmitted to depths at or below a skin surface in arange from about 20 mm to about 60 mm, or from about 40 mm to about 80mm, or from about 10 mm to about 40 mm, or from about 5 mm to about 40mm, or from about 0 mm to about 40 mm, or from about 10 mm to about 30mm, or from about 5 mm to about 30 mm, or from about 0 mm to about 30mm.

In various embodiments, a temperature of tissue receiving the ultrasoundenergy can be in a range from 30° C. to about 100° C., or from 43° C. toabout 60° C., or from 50° C. to about 70° C., or from 30° C. to about50° C., or from 43° C. to about 100° C., or from 33° C. to about 100°C., or from 30° C. to about 65° C., or from 33° C. to about 70° C., aswell as variations thereof.

Also, depending at least in part upon a specific biological effect andthe tissue layers that are targeted, temperature of tissue receiving theultrasound energy within ROI 215 may change in a range fromapproximately 10° C. to about 15° C. In various embodiments, atemperature of tissue receiving the ultrasound energy is raised to atemperature in a range from about 40° C. to about 55° C., or from about43° C. to about 48° C., or below a threshold of ablation of the tissue.

Moving to FIG. 2, a graph illustrates efficiency of an ultrasoundtransducer at specific frequency f_(c), in accordance with variousembodiments. Efficiency of a transducer is defined as the ratio of thepower output in the desired form to the total power input.Mathematically, if P_(in) represents the total power input and P_(out)represents the power output in the desired form, then the efficiency E,as a ratio between 0 and 1, is given by:

E=P _(out) /P _(in)  Equation 1

If E % represents the efficiency as a percentage, then:

E%=100P _(out) /P _(in)  Equation 2

In general, a transducer is not 100% efficient and power is typicallylost during the operation of the transducer in the form of heat.However, for a high-Q transducer, efficiency can approach 100% and heatgenerated by the transducer is minimized. A transducer is most efficientat specific frequency f_(c), as illustrated in FIG. 2. The transducerhas the maximum power output at frequency f_(c).

When a transducer operates, the transducer heats up over time and thetemperature of the transducer changes. As the temperature of thetransducer changes, the resonant frequency will shift towards frequencyf_(t), as illustrated in FIG. 3. This frequency shift decreases theefficiency of the transducer and, the power output from the transduceris significantly lower in the example of FIG. 3 as compared to theexample of FIG. 2.

Transducer efficiency decreases due to changes in temperature of thetransducer as a function of time. In addition, a change in temperatureof the transducer will cause a frequency shift. The frequency shiftchanges as a function of increasing temperature of the transducer. Afrequency shift decreases efficiency and can cause a system to changetotal power input to make up for a loss of power applied by thetransducer. A frequency shift will change the impedance of thetransducer.

In various embodiments, systems and methods, described herein, monitortransducer temperature and report changes in temperature to a controllerto modify the frequency generation to the transducer. In variousembodiments, systems and methods can monitor transducer temperature andreport changes in temperature to a controller to modify the total powerinput to the transducer. In various embodiments, systems and methods canmonitor efficiency and controls transducer temperature to prevent energytransmission from a shift in frequency.

In various embodiments, systems and methods can at least one of monitortransducer temperature and control transducer temperature. In variousembodiments, systems and methods can operate the transducer to at ornear maximum efficiency of power over a period of time. In variousembodiments, systems and methods can operate the transducer to at ornear maximum efficiency of power as a temperature of the transducerchanges. In various embodiments, systems and methods can modifytemperature of the transducer to maintain operation at or near maximumefficiency of power. In various embodiments, systems and methods canprevent a change in impedance of the transducer.

In some embodiments, energy emission, such as, an ultrasound emission,can be directed to targeted tissue to initiate a desired treatment tothe targeted tissue. If the power of the energy emission, such as, anultrasound emission, is too high, the targeted tissue can be permanentlydamaged, which provide pain to the patient being treated. In addition,if the power of the energy emission, such as, an ultrasound emission, istoo high, the desired treatment to the targeted tissue may not beeffective. If the power of the energy emission, such as, an ultrasoundemission, is too low, the desired treatment to the targeted tissue maynot be effective.

If the efficiency of the transducer degrades, the power of energyemission decreases. If the temperature of the transducer changes, theefficiency of the transducer changes and the power of energy emissiondecreases. For the most effective treatment to targeted tissue, power ofenergy emission is constant. Various embodiments provide methods andsystems to provide constant energy emission from transducer 110 that isdirected to targeted tissue.

Referring to FIG. 4, system 131 is illustrated, in accordance with someembodiments. System 131 can comprise drivers 102, power sensor 104,transducer 110, controller 115, and oscillator 120. In variousembodiments, oscillator 120 generates a frequency which is communicatedto drivers 102 to power transducer 110 to produce energy transmission150 at the frequency. Oscillator 120 can be an oscillator or anyfrequency generator, now known or later developed. For example,oscillator 120 can be but is not limited to, a function generator, afrequency generator, a waveform generator, a signal generator, pitchgenerator, a wave generator, or a pulse generator, frequencysynthesizer, direct digital synthesizer, or combinations thereof. Insome embodiments, oscillator 120 can be combined with or integrated todrivers 102. In some embodiments, oscillator 120 is programmable. Insome embodiments, controller 115 can be combined with or integrated toat least one of oscillator 120 and drivers 102. In some embodiments,power sensor 104 can be combined with or integrated to at least one ofoscillator 120, controller 115 and drivers 102. In some embodiments,power sensor 104 can be combined with or integrated to at least one ofoscillator 120, and drivers 102. In some embodiments, power sensor 104can be combined with or integrated to at least one of controller 115 anddrivers 102. In some embodiments, power sensor 104 can be combined withor integrated to at least one of oscillator 120, and controller 115. Insome embodiments, power sensor 104 can be combined with or integrated todrivers 102. In some embodiments, power sensor 104 can be combined withor integrated to oscillator 120. In some embodiments, power sensor 104can be combined with or integrated to controller 115.

In some embodiments, power sensor 104 monitors power input from drivers102 to transducer 110. In some embodiments, power sensor 104communicates with controller 115, which controls oscillator 120. In someembodiments, controller 115 receives signal from power sensor 104 andcontrols a frequency generated by oscillator 120 based on the receivedsignal. In some embodiments, power sensor 104 communicates a power levelof the power input from drivers 102.

As transducer 110 efficiency of energy transmission 150 degrades, forexample as illustrated in FIG. 3, drivers 102 changes the power input totransducer 110. In some embodiments, power sensor 104 detects the changein power input to transducer 110 and communicates with controller 115,which controls oscillator 120 to change in the power level of the powerinput from supply and/or drivers 102. In some embodiments, oscillator120 generates a correction to the frequency which is communicated to thedrivers 102, which is based on the communication from the power sensor104. In some embodiments, the correction to the frequency lowers thepower level of power input from drivers 102. In some embodiments, energytransmission 150 is corrected to specific frequency Q as illustrated inFIG. 2. If this correction to specific frequency f does not lower thepower input from the drivers 102 to transducer 110 below a threshold,power sensor 104 communicates this elevated power level to controller115, which controls oscillator 120 for another generation of acorrection to the frequency. In some embodiments, system 131 comprises ashut off power function, which is initiated if power sensor 104 detectsa power level that is above a predetermined threshold. In someembodiments, the shut off power function prevents the damaging ordestroying of transducer 110.

In some embodiments, the thickness of the transduction element oftransducer 110 may be configured to be uniform. That is, thetransduction element may be configured to have a thickness that isgenerally substantially the same throughout. In another exemplaryembodiment, the transduction element may also be configured with avariable thickness, and/or as a multiple damped device. For example, thetransduction element of transducer 110 may be configured to have a firstthickness selected to provide a specific operating frequency of a lowerrange, for example from approximately 1 kHz to 3 MHz. The transductionelement may also be configured with a second thickness selected toprovide a specific operating frequency of a higher range, for examplefrom approximately 3 to 100 MHz or other frequency ranges describedherein.

In yet another exemplary embodiment, transducer 110 may be configured asa single broadband transducer excited with two or more frequencies toprovide an adequate output for raising the temperature within ROI 215 tothe desired level. Transducer 110 may also be configured as two or moreindividual transducers, wherein each transducer 110 may comprise atransduction element. The thickness of the transduction elements may beconfigured to provide specific-operating frequencies in a desiredtreatment range. For example, in some embodiments, transducer 110 maycomprise a first transducer 110 configured with a first transductionelement having a thickness corresponding to a specific frequency rangeof approximately 1 MHz to 3 MHz, and a second transducer 110 configuredwith a second transduction element having a thickness corresponding to aspecific frequency of approximately 3 MHz to 100 MHz or frequency rangesdescribed herein.

Moreover, in some embodiments, any variety of mechanical lenses orvariable focus lenses, e.g. liquid-filled lenses, may also be used tofocus and or defocus the energy field. For example, transducer 110 mayalso be configured with an electronic focusing array in combination withone or more transduction elements to facilitate changed flexibility intreating ROI 215. Array may be configured in a manner similar totransducer 110. That is, array may be configured as an array ofelectronic apertures that may be operated by a variety of phases viavariable electronic time delays. Accordingly, the electronic aperturesof array may be manipulated, driven, used, configured to produce and/ordeliver energy in a manner corresponding to the phase variation causedby the electronic time delay. For example, these phase variations may beused to deliver defocused beams, planar beams, and/or focused beams,each of which may be used in combination to achieve differentphysiological effects in ROI 215.

Transduction elements may be configured to be concave, convex, and/orplanar. For example, transduction elements can be configured to beconcave in order to provide focused energy for treatment of ROI 215. Inanother exemplary embodiment, transduction elements may be configured tobe substantially flat in order to provide substantially uniform energyto ROI 215. In addition, transduction elements may be configured to beany combination of concave, convex, and/or substantially flatstructures. For example, a first transduction element may be configuredto be concave, while a second transduction element may be configured tobe substantially flat.

Moreover, transduction element can be any distance from the skin surface204. In that regard, it can be far away from the skin surface 204disposed within a long transducer 110 or it can be just a fewmillimeters from skin surface 204. In certain exemplary embodiments,positioning the transduction element closer to skin surface 204 isbetter for transmitting ultrasound at high frequencies. Moreover, bothtwo and three dimensional arrays of transduction elements can be used invarious embodiments.

In some embodiments, transducer 110 may also be configured as an annulararray to provide planar, focused and/or defocused acoustical energy. Forexample, in some embodiments, an annular array may comprise a pluralityof rings. Rings may be mechanically and electrically isolated into a setof individual elements, and may create planar, focused, or defocusedwaves. For example, such waves can be specified on-axis, such as bymethods of adjusting corresponding phase delays. An electronic focus maybe moved along various depth positions in ROI 215, and may enablevariable strength or beam tightness, while an electronic defocus mayhave varying amounts of defocusing. In some embodiments, a lens and/orconvex or concave shaped annular array may also be provided to aidfocusing or defocusing such that any time differential delays can bereduced. Movement of annular array in one, two or three-dimensions, oralong any path, such as through use of probes, motion mechanisms, anyconventional robotic arm mechanisms, and the like may be implemented toscan and/or treat a volume or any corresponding space within ROI 215.

In FIG. 5, system 132 is illustrated, in accordance with someembodiments. System 132 can comprise drivers 102, transducer 110,piezoelectric sensor 124, controller 115, and oscillator 120. In someembodiments, piezoelectric sensor 124 can be combined with or integratedto at least one of oscillator 120 and drivers 102. In some embodiments,piezoelectric sensor 124 can be combined with or integrated intooscillator 120. In some embodiments, piezoelectric sensor 124 can becombined with into integrated to drivers 102. In various embodiments,oscillator 120 generates a frequency which is communicated to drivers102 to power transducer 110 to produce energy transmission 150 at thefrequency. In some embodiments, piezoelectric sensor 124 monitors heatgenerated by transducer 110. In some embodiments, piezoelectric sensor124 is coupled to transducer 110. In some embodiments, piezoelectricsensor 124 is integrated to transducer 110. For example, piezoelectricsensor 124 may be a portion of transducer 110, which that is isolated orinsulation from the rest of transducer 110, and may comprise identicalmaterials as transducer 110. However, in one aspect of this example,piezoelectric sensor 124 has the opposite temperature coefficient oftransducer (same coefficient but opposite sign) and the piezoelectricsensor 124 changes temperature at the same rate as transducer 110, thuscompensating for changes in temperature of transducer 110.

Piezoelectric sensor 124 can comprise ceramic, or any other material orcombination of material described herein. In some embodiments,piezoelectric sensor 124 is configured with a temperature coefficientthat is lower than the temperature coefficient of transducer 110. Insome embodiments, piezoelectric sensor 124 is configured withtemperature coefficient, which is negative. In various embodiments,piezoelectric sensor 124 generates an electric potential in response toa temperature change, and communicates this electric potential tocontroller 115, which controls oscillator 120. In some embodiments,piezoelectric sensor 124 communicates with oscillator 120. In someembodiments, controller 115 receives signal from piezoelectric sensor124 and controls a frequency generated by oscillator 120 based on thereceived signal. In some embodiments, piezoelectric sensor 124communicates the heat generated by transducer 110, which can becommunicated using temperature.

As transducer 110 efficiency of energy transmission 150 degrades, forexample as illustrated in FIG. 3, heat generated by transducer 110changes. For example, drivers 102 changes the power input to transducer110, which can change the heat generated by transducer 110. In someembodiments, piezoelectric sensor 124 detects the change in heatgeneration by transducer 110 and communicates with controller 115, whichcontrols oscillator 120, the change in heat generation. In someembodiments, oscillator 120 generates a correction to the frequencywhich is communicated to the drivers 102, which is based on thecommunication from the piezoelectric device 124. In some embodiments,the correction to the frequency lowers the power level of power inputfrom drivers 102, which can lower the amount of heat that is generatedby transducer 110. In some embodiments, the correction to the frequencylowers the power level of power input from drivers 102. In someembodiments, energy transmission 150 is corrected to specific frequencyf_(c) as illustrated in FIG. 2. If this correction to specific frequencyf_(c) does not lower the power input from the drivers 102 to transducer110 below a threshold, piezoelectric sensor 124 communicates thiselevated heat generation by transducer 110 to oscillator 124 for anothergeneration of a correction to the frequency. In some embodiments, system132 comprises a shut off power function, which is initiated ifpiezoelectric sensor 124 detects a heat generation level or atemperature of transducer 110 is above a predetermined threshold. Insome embodiments, the shut off power function prevents the damaging ordestroying of transducer 110.

Turning to FIG. 6, system 133 is illustrated, in accordance with someembodiments. System 133 can comprise drivers 102, transducer 110,temperature sensor 127, and oscillator 120. In some embodiments,temperature sensor 127 can be combined with or integrated to at leastone of oscillator 120 and drivers 102. In various embodiments,oscillator 120 generates a frequency which is communicated to drivers102 to power transducer 110 to produce energy transmission 150 at thefrequency. In some embodiments, temperature sensor 127 monitorstemperature of transducer 110. In some embodiments, temperature sensor127 coupled to transducer 110. In some embodiments, temperature sensor127 is integrated to transducer 110. Temperature sensor 127 can be anysuitable temperature sensor, now known or later developed. In someembodiments, temperature sensor 127 communicates with controller 115,which communicates with oscillator 120. In some embodiments, temperaturesensor 127 communicates with oscillator 120. In some embodiments,controller 115 receives signal from temperature sensor 127 and controlsa frequency generated by oscillator 120 based on the received signal. Insome embodiments, temperature sensor 127 communicates the temperature ofby transducer 110.

As transducer 110 efficiency of energy transmission 150 degrades, forexample as illustrated in FIG. 3, heat generated by transducer 110changes. For example, drivers 102 changes the power input to transducer110, which can change the heat generated by transducer 110. In someembodiments, temperature sensor 127 detects the change in heatgeneration by transducer 110 and communicates with controller 115, whichcontrols oscillator 120, the change in heat generation. In someembodiments, oscillator 120 generates a correction to the frequencywhich is communicated to the drivers 102, which is based on thecommunication from the piezoelectric device 124. In some embodiments,the correction to the frequency lowers the power level of power inputfrom drivers 102, which can lower the amount of heat that is generatedby transducer 110. In some embodiments, the correction to the frequencylowers the power level of power input from drivers 102. In someembodiments, energy transmission 150 is corrected to specific frequencyf_(c) as illustrated in FIG. 2. If this correction to specific frequencyf_(c) does not lower the power input from the drivers 102 to transducer110 below a threshold, temperature sensor 127 communicates this elevatedheat generation by transducer 110 to oscillator 124 for anothergeneration of a correction to the frequency. In some embodiments, system132 comprises a shut off power function, which is initiated iftemperature sensor 127 detects a heat generation level or a temperatureof transducer 110 is above a predetermined threshold. In someembodiments, the shut off power function prevents the damaging ordestroying of transducer 110.

Moving to FIG. 7, system 135 is illustrated, in accordance with someembodiments. System 135 can comprise drivers 102, voltage monitor 105,transducer 110, controller 115, and oscillator 120. In variousembodiments, oscillator 120 generates a frequency which is communicatedto drivers 102 to power transducer 110 to produce energy transmission150 at the frequency. Oscillator 120 can be an oscillator or anyfrequency generator, now known or later developed. For example,oscillator 120 can be but is not limited to, a function generator, afrequency generator, a waveform generator, a signal generator, pitchgenerator, a wave generator, or a pulse generator, frequencysynthesizer, direct digital synthesizer, or combinations thereof. Insome embodiments, oscillator 120 can be combined with or integrated todrivers 102. In some embodiments, oscillator 120 is programmable. Insome embodiments, controller 115 can be combined with or integrated toat least one of oscillator 120 and drivers 102. In some embodiments,voltage monitor 105 can be combined with or integrated to at least oneof oscillator 120, controller 115 and drivers 102. In some embodiments,voltage monitor 105 can be combined with or integrated to at least oneof oscillator 120, and drivers 102. In some embodiments, voltage monitor105 can be combined with or integrated to at least one of controller 115and drivers 102. In some embodiments, voltage monitor 105 can becombined with or integrated to at least one of oscillator 120, andcontroller 115. In some embodiments, voltage monitor 105 can be combinedwith or integrated to drivers 102. In some embodiments, voltage monitor105 can be combined with or integrated to oscillator 120. In someembodiments, voltage monitor 105 can be combined with or integrated tocontroller 115. In some embodiments, voltage monitor 105 monitorsvoltage of power from drivers 102 to transducer 110. In someembodiments, voltage monitor 105 communicates with controller 115, whichcontrols oscillator 120. In some embodiments, controller 115 receivessignal from voltage monitor 105 and controls a frequency generated byoscillator 120 based on the received signal. In some embodiments,voltage monitor 105 communicates a voltage level of the voltage of powerfrom drivers 102.

As transducer 110 efficiency of energy transmission 150 degrades, forexample as illustrated in FIG. 3, drivers 102 changes the voltage ofpower to transducer 110. In some embodiments, voltage monitor 105detects the increase in voltage of power to transducer 110 andcommunicates with controller 115, which controls oscillator 120 tochange in the voltage level of the voltage of power from supply and/ordrivers 102. In some embodiments, oscillator 120 generates a correctionto the frequency which is communicated to the drivers 102, which isbased on the communication from the voltage monitor 105. In someembodiments, the correction to the frequency lowers the voltage level ofvoltage of power from drivers 102. In some embodiments, energytransmission 150 is corrected to specific frequency fc as illustrated inFIG. 2. If this correction to specific frequency fc does not lower thevoltage of power from the drivers 102 to transducer 110 below athreshold, voltage monitor 105 communicates this elevated voltage levelto controller 115, which controls oscillator 120 for another generationof a correction to the frequency. In some embodiments, system 135comprises a shut off power function, which is initiated if voltagemonitor 105 detects a voltage level that is above a predeterminedthreshold. In some embodiments, the shut off power function prevents thedamaging or destroying of transducer 110.

FIG. 8 With reference to FIG. 8, system 135 is illustrated, inaccordance with some embodiments. System 135 can comprise drivers 102,transducer 110, temperature sensor 127, and oscillator 120. In someembodiments, temperature sensor 127 can be combined with or integratedto at least one of oscillator 120 and drivers 102. In variousembodiments, oscillator 120 generates a frequency which is communicatedto drivers 102 to power transducer 110 to produce energy transmission150 at the frequency. In some embodiments, temperature sensor 127monitors temperature of transducer 110. In some embodiments, temperaturesensor 127 coupled to transducer 110. In some embodiments, temperaturesensor 127 is integrated to transducer 110. Temperature sensor 127 canbe any suitable temperature sensor, now known or later developed. Insome embodiments, temperature sensor 127 communicates with controller115, which communicates with oscillator 120. In some embodiments,temperature sensor 127 communicates with oscillator 120. In someembodiments, controller 115 receives signal from temperature sensor 127and controls a frequency generated by oscillator 120 based on thereceived signal. In some embodiments, temperature sensor 127communicates the temperature of by transducer 110. As transducer 110efficiency of energy transmission 150 degrades, for example asillustrated in FIG. 3, drivers 102 changes the power to transducer 110,which change the voltage across the transducer 110. In some embodiments,controller 115 detects the change in voltage across transducer 110 andcommunicates with controller 115. In some embodiments, oscillator 120generates a correction to the frequency which is communicated to thedrivers 102, which is based on the communication from controller 115. Insome embodiments, the correction to the frequency lowers the voltagelevel of voltage across transducer 110. In some embodiments, energytransmission 150 is corrected to specific frequency fc as illustrated inFIG. 2. If this correction to specific frequency fc does not lower thevoltage across transducer 110 below a threshold, controller 115communicates this elevated voltage level to oscillator 120 for anothergeneration of a correction to the frequency.

As transducer 110 efficiency of energy transmission 150 degrades, forexample as illustrated in FIG. 3, heat generated by transducer 110changes. For example, drivers 102 changes the power input to transducer110, which can change the heat generated by transducer 110. In someembodiments, temperature sensor 127 detects the change in heatgeneration by transducer 110 and communicates with controller 115, whichcontrols oscillator 120, the change in heat generation. In someembodiments, oscillator 120 generates a correction to the frequencywhich is communicated to the drivers 102, which is based on thecommunication from the piezoelectric device 124. In some embodiments,the correction to the frequency lowers the power level of power inputfrom drivers 102, which can lower the amount of heat that is generatedby transducer 110. In some embodiments, the correction to the frequencylowers the power level of power input from drivers 102. In someembodiments, energy transmission 150 is corrected to specific frequencyfc as illustrated in FIG. 2. If this correction to specific frequency fcdoes not lower the power input from the drivers 102 to transducer 110below a threshold, temperature sensor 127 communicates this elevatedheat generation by transducer 110 to oscillator 124 for anothergeneration of a correction to the frequency. In some embodiments, system132 comprises a shut off power function, which is initiated iftemperature sensor 127 detects a heat generation level or a temperatureof transducer 110 is above a predetermined threshold. In someembodiments, the shut off power function prevents the damaging ordestroying of transducer 110.

Various embodiments provide a method of sensing coupling of anultrasound source to a target. In some embodiments, the method comprisesproviding an ultrasound sound source comprising a transducer, anacoustically transparent standoff, an acoustic window at a bottomsurface of the standoff, and a frequency sweep function coupled to thetransducer. In some embodiments, the method can comprise emittingultrasound energy from the transducer; receiving reflected energy;frequency sweeping the transducer; determining the feedback from thefrequency sweep is above a threshold level; and determining of thesource is coupled to the target.

In some embodiments, if the feedback from the frequency is above thethreshold level, then the source is not coupled to the target. In someembodiments, if the feedback from the frequency is below the thresholdlevel, then the source is coupled to the target.

In some embodiments, the window is a half wavelength thick. In someembodiments, the method can further comprise providing constant averageoutput power from the source. In some embodiments, the method canfurther comprise terminating power to the source. In some embodiments,the sweep frequency has a period, which is calculated using a pathlength of the standoff and the speed of sound. In some embodiments, themethod can further comprise comprising providing ultrasound energy to atarget.

Various embodiments provide a system for determining whether anultrasound source is coupled to a target. In some embodiments, thesystem comprises an ultrasound source comprising a transducer; anacoustically transparent standoff coupled to the transducer; a halfwavelength acoustic window at a bottom surface of the standoff, and afrequency sweep function coupled to the transducer.

In some embodiments, the half wavelength acoustic window is a reflectorwhen the ultrasound source is not coupled to the target.

In some embodiments, the half wavelength acoustic window is transparentto ultrasound energy when the ultrasound source is coupled to thetarget. In some embodiments, the system can further comprise a power totransducer termination function in communication with the frequencysweep function.

In some embodiments, the frequency sweep function provides a constantaverage output power from the ultrasound source when the ultrasoundsource is coupled to the target. In some embodiments, the system canfurther comprise a lens coupled to the ultrasound source.

Various embodiments provide a system for providing a constant averageoutput of power from an ultrasound source. In some embodiments, thesystem comprises an ultrasound transducer coupled to a power supply; acontroller in communication with the power supply; a chirp function incommunication with and operable to monitor the ultrasound transducer; afeedback loop from the chirp function to the controller. In someembodiments, the controller is operable to change a parameter on thetransducer based on the feedback to provide a constant average output ofpower from the ultrasound transducer.

In some embodiments, the system can further comprise a coupling devicein acoustic communication with the ultrasound transducer. In someembodiments, the system can further comprise a half wavelength acousticwindow in acoustic communication with the ultrasound transducer.

In some embodiments the coupling device contains a medium configured tobe transparent to ultrasound energy. In some embodiments, the system canfurther comprise a contact sensor operable to determine if theultrasound transducer is coupled to a target. In some embodiments, thecontroller is operable to control the power supply to change an amountof power provided to the ultrasound transducer.

In various embodiments, ultrasound probe 205 can comprise a tissuecontact sensor. In some embodiments, tissue contact sensor communicateswhether ultrasound probe 205 is coupled to the ROI 215. The tissuecontact sensor may measure a capacity of a skin surface 204 above theROI 215 and communicate a difference between the capacitance of thecontact to the skin surface 204 and the capacitance of air. In someembodiments, the tissue contact sensor is initiated or turned on bypressing ultrasound probe against skin surface 204.

In various embodiments, as illustrated in FIGS. 9 and 10, a couplingdevice having a coupling sensor system is illustrated. Coupling device130 comprises enclosure 132 which can be filled with coupling medium135. Coupling device 130 further comprises a window 140 which isessentially transparent to ultrasound energy. In some embodiments,coupling device 130 comprises transducer 110. In some embodiments,coupling device 130 may comprise matching layer and/or lens 113.Coupling device 130 is part of or connects to probe 205. In someembodiments, transducer 110 is separate from the coupling device 130. Insome embodiments, transducer 110 and matching layer and/or lens 113 areseparate from coupling device 130. Coupling device 130 comprises pathlength 144, which is the distance from transducer 110 to window 140.

In some embodiments, coupling device 130 is configured to provideultrasound energy 150 to ROI 215. In some embodiments, coupling device130 is configured to provide focused ultrasound energy 150 to ROI 215.In some embodiments, coupling device 130 is configured to provideunfocused ultrasound energy 150 to ROI 215. In some embodiments,coupling device 130 is configured to provide defocused ultrasound energy150 to ROI 215.

In some embodiments, window 140 is a half wavelength (“k”) thick. Insome embodiments, window 140 is a multiple of a half wave length thick,such as, for example. 1.5 wavelength thick. Window 140 can comprise anynumber of materials that are temperature stable within up to about 150°C. (for example plastics and polymers) or to higher temperatures (forexample metals and alloys) and are able to be configured into ultrasoundtransmissive window having a multiple of a half wave length thick. Insome embodiments, window 140 can be configured using a cross linkedpolystyrene material or a PE imide material.

In some embodiments, enclosure 132 is essentially impermeable to water.Enclosure 132 contains medium 135, which can be water or saline solutionor other water based solution, a gel, or a solid. Medium 135 isessentially transparent to acoustic energy. In some embodiments, medium135 has acoustic impedance very similar to or the same as tissue in theROI 215. In some embodiments, medium 135 has acoustic impedance verysimilar to or the same as skin surface.

In some embodiments, ultrasound energy 150 is a continuous waveemission. As illustrated in FIG. 9, coupling device 130 couplestransducer 110 to ROI 205 and facilitates the transfer of ultrasoundenergy 150 from transducer 110 through medium 135 and window 140 andinto ROI 215. However, as illustrated in FIG. 10, if coupling device isuncoupled from ROI 205 and is coupled to air, window 140 becomes areflector and reflects all or at least a majority of ultrasound energy150 back to transducer as reflected energy 155.

In some embodiments, a DDS synthesizer and be coupler to transducer 110and configured to frequency sweep transducer 110. In some embodiments,frequency sweep can monitor the constant average output power oftransducer 110. In some embodiments, frequency sweep can be a stepfunction of a set of different frequencies. In some embodiments, thefrequency sweep is a chirp function. In some embodiments, the stepfunction of a set of different frequencies can comprise a plurality ofdifferent frequencies. In some embodiments, the period of each sweep is50 kHz. This sweep period is calculated using path length 144 equal to15 mm and a time of flight of 20 microseconds. In some embodiments, theperiod of each sweep is 23 kHz. This sweep period is calculated usingpath length 144 equal to 32.6 mm and a time of flight of 43.5microseconds. Using path length 144 and the time of flight of theultrasound energy 150, an appropriate sweep period can be calculated formost configurations of coupling device 130.

In some embodiments, an output from the frequency sweep can be monitoredas illustrated in FIGS. 11 and 12. The units for axis of the graphs inFIGS. 11 and 12 are resistance in the y axis and frequency in the xaxis. FIG. 11 illustrates the feedback from a frequency sweep whencoupling device 130 is coupled to ROI 215 as illustrated in FIG. 9. FIG.12 illustrates the feedback from a frequency sweep when coupling device130 is uncoupled (or coupled to air) as illustrated in FIG. 10. Thisdifference in feedback from the frequency sweep can be a contact sensor.If the frequency sweep reports feedback is similar to FIG. 11, probe 205continues to function providing ultrasound energy 150 to ROI 215. If thefrequency sweep reports feedback is similar to FIG. 12, probe 205 isshut down as a safety mechanism and/or to protect the transducer frombeing damaged or destroyed.

In some embodiments, frequency sweep can monitor and adjust output powerto achieve a constant average output power, even with variations in themedium 135 temperature and/or transducer 110 temperature. In variousembodiments, contact sensor system can be combined with one or moredifferent sensing techniques. For example, contact sensor can becombined with a hall detector. For example, contact sensor can becombined with an optical detector. For example, contact sensor can becombined with a conductive detector. For example, contact sensor can becombined with a piezo electric detector. For example, contact sensor canbe combined with a mechanical detector. For example, contact sensor canbe combined with a magnetic detector. In various embodiments, contactsensor system can be combined with at least one of a hall detector,optical detector, an acoustic impedance detector, a conductive detector,a piezo electric detector, a mechanical detector, a magnetic detector,an acoustic impedance detector, and combinations thereof.

In some embodiments, coupling device 130 can comprise a temperaturesensor. In some embodiments, coupling device 130 can comprise twotemperature sensors. For example, one of the temperature sensors can bein contact with medium 135 and the second temperature sensor can be incontact with transducer 110. In some embodiments, if the temperature asreported by a temperature is above 43° C., probes 205 stop emission ofultrasound energy 150.

The following patents and patent applications are incorporated byreference: US Patent Application Publication No. 20050256406, entitled“Method and System for Controlled Scanning, Imaging, and/or Therapy”published Nov. 17, 2005; US Patent Application Publication No.20060058664, entitled “System and Method for Variable Depth UltrasoundTreatment” published Mar. 16, 2006; US Patent Application PublicationNo. 20060084891, entitled Method and System for Ultra-High FrequencyUltrasound Treatment” published Apr. 20, 2006; U.S. Pat. No. 7,530,958,entitled “Method and System for Combined Ultrasound Treatment” issuedMay 12, 2009; US Patent Application Publication No. 2008071255, entitled“Method and System for Treating Muscle, Tendon, Ligament, and CartilageTissue” published Mar. 20, 2008; U.S. Pat. No. 6,623,430, entitled“Method and Apparatus for Safely Delivering Medicants to a Region ofTissue Using Imaging, Therapy, and Temperature Monitoring UltrasonicSystem, issued Sep. 23, 2003; U.S. Pat. No. 7,571,336, entitled “Methodand System for Enhancing Safety with Medical Peripheral Device byMonitoring if Host Computer is AC Powered” issued Aug. 4, 2009; USPatent Application Publication No. 20080281255, entitled “Methods andSystems for Modulating Medicants Using Acoustic Energy” published Nov.13, 2008; US Patent Application Publication No. 20060116671, entitled“Method and System for Controlled Thermal Injury of Human SuperficialTissue,” published Jun. 1, 2006; US Patent Application Publication No.20060111744, entitled “Method and System for Treatment of Sweat Glands,”published May 25, 2006; US Patent Application Publication No.20080294073, entitled “Method and System for Non-Ablative Acne Treatmentand Prevention,” published Oct. 8, 2009; U.S. Pat. No. 8,133,180,entitled “Method and System for Treating Cellulite,” issued Mar. 13,2012; U.S. Pat. No. 8,066,641, entitled “Method and System for PhotoagedTissue,” issued Nov. 29, 2011; U.S. Pat. No. 7,491,171, entitled “Methodand System for Treating Acne and Sebaceous Glands,” issued Feb. 17,2009; U.S. Pat. No. 7,615,016, entitled “Method and System for TreatingStretch Marks,” issued Nov. 10, 2009; and U.S. Pat. No. 7,530,356,entitled “Method and System for Noninvasive Mastopexy,” issued May 12,2009.

It is believed that the disclosure set forth above encompasses at leastone distinct invention with independent utility. While the invention hasbeen disclosed herein, the specific embodiments thereof as disclosed andillustrated herein are not to be considered in a limiting sense asnumerous variations are possible. The subject matter of the inventionsincludes all novel and non-obvious combinations and sub combinations ofthe various elements, features, functions and/or properties disclosedherein.

Various embodiments and the examples described herein are not intendedto be limiting in describing the full scope of systems and methods ofthis invention. Equivalent changes, modifications and variations ofvarious embodiments, materials, systems, and methods may be made withinthe scope of the present invention, with substantially similar results.

1. A method of sensing coupling of a ultrasound source to a target, themethod comprising: providing an ultrasound sound source comprising atransducer, an acoustically transparent standoff, an acoustic window ata bottom surface of the standoff, and a frequency sweep function coupledto the transducer; emitting ultrasound energy from the transducer;receiving reflected energy; frequency sweeping the transducer;determining the feedback from the frequency sweep is above a thresholdlevel; determining of the source is coupled to the target.
 2. The methodaccording to claim 1, wherein if the feedback from the frequency isabove the threshold level, then the source is not coupled to the target.3. The method according to claim 1, wherein if the feedback from thefrequency is below the threshold level, then the source is coupled tothe target.
 4. The method according to claim 1, wherein the window is ahalf wavelength thick.
 5. The method according to claim 3, furthercomprising providing constant average output power from the source. 6.The method according to claim 2, terminating power to the source.
 7. Themethod according to claim 1, wherein the sweep frequency has a period,which is calculated using a path length of the standoff and the speed ofsound.
 8. The method according to claim 3 further comprising providingultrasound energy to a target.
 9. A system for determining whether anultrasound source is coupled to a target, the system comprising: anultrasound source comprising a transducer; an acoustically transparentstandoff coupled to the transducer; an half wavelength acoustic windowat a bottom surface of the standoff, and a frequency sweep functioncoupled to the transducer.
 10. The system according to claim 9, whereinthe half wavelength acoustic window is a reflector when the ultrasoundsource is not coupled to the target.
 11. The system according to claim9, wherein the half wavelength acoustic window is transparent toultrasound energy when the ultrasound source is coupled to the target.12. The system according to claim 9, further comprising a power totransducer termination function in communication with the frequencysweep function.
 13. The system according to claim 9 wherein thefrequency sweep function provides a constant average output power fromthe ultrasound source when the ultrasound source is coupled to thetarget.
 14. The system according to claim 9, further comprising a lenscoupled to the ultrasound source.
 15. A system for providing a constantaverage output of power from an ultrasound source, the systemcomprising: an ultrasound transducer coupled to a power supply; acontroller in communication with the power supply; a chirp function incommunication with and operable to monitor the ultrasound transducer; afeedback loop from the chirp function to the controller; wherein thecontroller is operable to change a parameter on the transducer based onthe feedback to provide a constant average output of power from theultrasound transducer.
 16. The system according to claim 15 furthercomprising a coupling device in acoustic communication with theultrasound transducer.
 17. The system according to claim 16, furthercomprising a half wavelength acoustic window in acoustic communicationwith the ultrasound transducer.
 18. The system according to claim 15,wherein the coupling device contains a medium configured to betransparent to ultrasound energy.
 19. The system according to claim 15,further comprising a contact sensor operable to determine if theultrasound transducer is coupled to a target.
 20. The system accordingto claim 15, wherein the controller operable to control the power supplyto change an amount of power provided to the ultrasound transducer.